The effect of pH on the photocatalytic degradation of methyl orange using decorated ZnO nanoparticles with SnO₂ nanoparticles

In this study we investigate for the first time the effect of pH on the photocatalytic activity of SnO₂ nanoparticles, ZnO nanoparticles and hybrids containing decorated ZnO nanoparticles with difference amount of SnO₂ nanoparticles (ZnO–SnO₂ (1–0.5) and ZnO–SnO₂ (1–2)). The experimental results show that the removal efficiency of methyl orange increases with respect to the irradiation time in all of the tested suspensions. Meanwhile, the effect of pH confirm that the removal efficiency of pollutant in the suspension with natural pH (pH = 7) is higher than that of acidic (pH = 4) and alkaline condition (pH = 10). The results of statistical analysis reveal that the irradiation time and pH have significant impact on the photocatalytic activity of all nanoparticles and hybrids. The coefficient of determination of all proposed models justify that the proposed models can be successfully predicted the removal efficiency of methyl orange in the all suspensions. The results of Duncan’s multiple range test (α = 0.05) demonstrate that there is a significant difference between different levels of pH. Also, the photocatalytic activity of hybrid increase by increasing the decorated SnO₂ nanoparticles content.